[Synergistic antimicrobial efficacy of 2% chlorhexidine and 3% hydrogen peroxide for infected root canals of extracted human teeth: an ex-vivo study]

An endodontic irrigation solution with low toxicity and high antimicrobial activity is required in the process of endodontic treatment. Using a combination of intracanal irrigants is one solution to achieve this goal. The aim of this study was to evaluate the synergistic antimicrobial efficacy of chlorhexidine and hydrogen peroxide against bacteria in the infected extracted human root canals. Forty-two teeth with periapical lesions were chosen for this study. The teeth were extracted and preserved in normal saline at 37°C for less than 24 hours. Canals were prepared with nickel titanium rotary files [S1 to F3] and irrigated with 10cc of the respective irrigants [group 1:14 teeth irrigated with 3% hydrogen peroxide; group 2: 14 teeth irrigated with 2% chlorhexidine and group 3: 14 teeth irrigated with a combination of 3% hydrogen peroxide and 2% chlorhexidine]. Samples were obtained with paper cones before and after root canal preparation [S1, S2] and transferred to a microbiology lab for colony counting. Data were analyzed using the Kruskal-Wallis and Mann-Whitney tests. The results showed that all the understudy irrigants significantly decreased the bacterial colony count. A combination of chlorhexidine and hydrogen peroxide was significantly more effective than hydrogen peroxide. Chlorhexidine is an effective irrigant with high antimicrobial activity but its antimicrobial efficacy does not significantly increase in combination with hydrogen peroxide

[Comparison of the effects of bupivacaine and lidocaine as local anesthetics on the incidence of pain after root canal therapy]

Statement of Problem: Post-treatment endodontic pain is a concern of both patients and dentists. Several methods and drugs have been suggested to prevent the pain. In several studies, the use of long acting local anesthetics has been considered in the prevention of pain after some dental procedures

Purpose: The purpose of this study was to compare the effect of Bupivacaine and Lidocaine as local anesthetics on the incidence of pain after root canal therapy

Materials and Method: A total of 60 patients referring to 3 endodontists were invited to participate in this double blind clinical trial study. The patients had no history of cardiovascular disease, hypersensitivity to amide types of local anaesthetics, renal failure and hyperthyroidism. They were randomly assigned to one of the two groups: 0.5 percent Bupivacaine with 1.200000 Epinephrine or 2 percent Lidocaine with 1.100000 Epinephrine. After root canal therapy, the extent of postoperative pain was measured during 48 hours and categorized into 4 scores, 0 to 3. The results were analyzed using Mann-Whitney test for comparing the pain scores among the patients and Fischer's Exact test for evaluating the correlation between, sex, jaw position, type of pulpal disease and preoperative pain with postoperative pain

Results: Statistical analysis showed that Bupivacaine significantly reduced the incidence of flare-up after root canal therapy [p =0.002] and the need for analgesics was significantly decreased using Bupivacaine [p =0.01]

Conclusion: Long acting local anesthetics can be used in endodontic treatment especially for patients with high prediction of postoperative pain